In the past, thirteen speed transmissions and assemblies in trucks and the like have been controlled by means of a transmission shift lever in combination with a threeway air valve for supplying pneumatic pressure through a selected one of two fluid lines to the transmission. The air valve may be mounted on the shift lever as disclosed, for example, in U.S. Pat. No. 3,373,831 or it may be mounted at some other location. When accelerating, the driver moves the shift lever from each gear selection position to the next while simultaneously operating the air valve with his thumb or in some other manner. In this manner a 13 speed transmission can be controlled by moving the shift lever between only five gear selection positions. I have found those operations of the shift lever and the air valve control lever to be an unnatural movement of the hand which is thus very tiring in the course of a day. It would, therefore, be desirable to provide an improved method and apparatus for shifting the combination mechanically and pneumatically operated transmissions of the type commonly used in tractor trailers and known in the trade as Eaton and Spicer transmissions.